Should the log store format change?

[svenstorp]

Today all synced moves are stored as XML-files in ~/.openambit. Those XML-files are pretty space consuming, typically > 2 MB / hour of exercise. XML was chosen since it is easy to read, and compare to Moveslink. Possible options:

• Compressing the XML
• Leightweight database (for example SQLite)
• ???

[paddy-hack]

How about storing moves in the clock's native format? That should be pretty space efficient and all the code needed to interpret it is there already.

[svenstorp]

Pros and cons (without valuing them) about using clock's native format: Pros:

• Space efficient
• Unknown log data left untouched and can be correctly parsed when known

Cons:

• Virtually impossible to parse without libambit (for user scripts like the gpx python script)
• Future devices might have a different format (Ambit3 already changed format for all settings), leading to different format of different logs.
• Quite some calculations every time a move is opened (samples needs to be rearranged, relative times calculated etc).
• Metadata related to the move needs to be stored in a separate format/storage (for example Movescount-ID).

[svenstorp]

Pros and cons (without valuing them) about using compressed XMLs: Pros:

• Very small changes needed
• Easy to read and use by other applications

Cons:

• Not that space efficient

[paddy-hack]

Thanks for adding the pros and cons! I think that the preserving unknown log data for later is a big plus.

I would treat this as a storage format for the clock owners. They would need libambit anyway to get their data off the clock. If they want to "export" to something else like XML, that would not be too hard then. The export can then be used as input to things like the GPX Python script. Different native formats can be dealt with by storing clock/model information with it. This kind of metadata can be put in a header to the log data. Performance issues? That's something that has to be borne out in practice. It's not like XML processing is a speed monster.

[landas]

Closing issue without any recent activity. Feel free to reopen if issue is still relevant.